Process and apparatus for moistening paper



I 1,617,704 9 w. COLDITZ ET AL PROCESS AND APPARATUS FOR MOISTENING PAPER 'Filed Dec. 5, 1924 Patented Feb. 15, 1927.

UNITED STAT S- PATENT OFFICE.

v WALTER COLDITZ AND enone 'rnoMM L, or HILLEG'OSSEN, GERMANY, AssIeNoRs' 'ro THE FIRM KOHOLYT AKTIENGESELLSCHAFT, or BERLIN, GERMANY.

rnoonss AND APPARATUS FOR. ivrors'rnnnve PAPERQ Application filed December 5, 1924, Serial No. 754,210, and iiGermanyDecember 14, 1923.

one or both sides of theendless paper, for

instance by shattering it with water by means of brushes or spraying it with water by means of nozzles or by blowing steam on 1t, or by passing the paper over one or between two moistened felt strips. Another method consists in condensing steam on a cooling cylinder over which the paper is run whereby the condensed water is transferred from the cylinder jacket to the paper which is moistened thereby to a certain degree.

These known processes are disadvantageousin that the paper is npt uniformly moistened and therefore a long time is required for uniformly distributing the'moisture over the paper surface and to the in-- terior of the paper, such preparatory treatment forming the principal condition for obtaining a perfect satining of the paper. Therefore with these old processes one was obliged to store the moistened paper during more or less time to allow the moisture to "penetrate the paper through in a uniform manner.- In many cases it was also necessary to rewind and to remoisten the paper.

During the storing it is unavoidable that ess forming the object of the present inven-' tion. We have found that a uniform peneparts of' the paper coming in contact with the air, especially the edges, become dry.

I These drawbacks are'avoided by the proctration of the paper with moisture can be obtained by precipitating on it moisture out of the surrounding air This is efiected by cooling the conveying cylinders by means of a cooling machine to such a degree that the paper is cooled to a temperaturebelow that of the surrounding air, preferably below its dew-point, and moisture is precipitated on the paper. Of course the precipitation takes place in an extraordinarily uniform manner. By supplying air containinga suitable degree of moisture and by adjusting the temperature of the paper it is easily possible to control the degree of moisture in the paper. Therefore it is not necessary to rewind the paper and to ripen-it by storing, but the paper may be prepared for the satining process in one single operation.

The cooling of the'cylinders is efiected by means of a cooling machine, for instance by passing through them a cooling fluid such.

as brine which is cooled down by a-separate cooling machine, or by placing the evaporator of a cooling machine immediately in the interior of the cooling cylinder.

An apparatus for carrying out our invention is illustrated in a diagrammatic form in the accompanying drawing. Fig. 1 is a vertical section through the apparatus. Fig.

2 is a vertical section through. a modified form of the apparatus. Fig. 3 a diagram showing the manner in which the paper web is led over the cooling roll and the glazing rolls of the paper machine. In Figs. 1 and 2 K designates the cooling cylinder of the paper-machine, K the compressor, C the condenser, V the evaporator, R the-controlvalve of a cooling machine. In Fig. 1 F

designates the cooling fluid, for instance brinewhich is supplied by the pumpP to the cooling cylinder, the temperature of the cylinder K and the aper thereon being v regulated bymeans of t 1e valve R. In Fig.

2 the evaporator V is shown arranged. in

the interiorof the cooling cylinder K. Fig. 3 is a diagram showing the disposition ofthe paper-machine, K designating the cooling cylinder and T the drying'cylinders.

l. A- machine for moistening paper colnevaporatin .a fluid in the' interior of the said cylin er.

2. Process for moistening paper cons1st= in in leading the paper around a cooled -h o low cylinder, in contact with substantially the whole surface of said cylinder,

and then passing the paper through moist air,"

3. Process for moistening paper consist accordance with the degree of moisture ining in leading the paper around a cooled said moist air.

hollpw cy1inder,in contact with substantial- In testimony whereof we afiix our signaly the whole surface of said cylinder, then tures. 5 passing the paper through moist air and WALTER COLDITZ.

adjusting the temperature of the cylinder in GEORG THOMMEL. 

